Simplify the following expression: $p = \dfrac{4a - 10}{7} \div \dfrac{9a}{10}$
Answer: Dividing by an expression is the same as multiplying by its inverse. $p = \dfrac{4a - 10}{7} \times \dfrac{10}{9a}$ When multiplying fractions, we multiply the numerators and the denominators. $p = \dfrac{ (4a - 10) \times 10 } { 7 \times 9a}$ $p = \dfrac{40a - 100}{63a}$